People use utility vehicles for many purposes. Implements are often attached to the back or front of such utility vehicles to accomplish work. For example, utility vehicles may be used to pull implements including plows (to turn over the upper layer of soil), harrows (for breaking up clumps and clods of dirt), seed drills (for introducing seed to the soil), and sprayers (for introducing liquid herbicides, insecticides, or other chemicals). In many cases, workers attach such implements to the back of the utility vehicle using a 3-point hitch. (The term “utility vehicle” as used herein shall include, without limitation, tractors, ATVs, UTVs, trucks, and other similar vehicles.)
A 3-point hitch, which is a conventional component on many utility vehicles provides a way of attaching implements to the back of the vehicle. A 3-point hitch includes three movable arms: two lower lift arms and a single upper arm, known as the top link. When each of these three arms is attached to an implement, the terminal ends of the arms may be thought of as defining the three vertices of an upright triangle, or letter “A” (viewed by an observer facing the back of the utility vehicle). Furthermore, the lower lift arms are typically operable hydraulically, allowing a worker using a utility vehicle to pull an implement to adjust the height of the implement relative to the ground. Hydraulic operation is typically achieved by attaching the lower lift arms of the 3-point hitch—using connectors known as lift links—to hydraulically driven rockshaft arms. The operator actuates a control that hydraulically raises the rockshaft arms; which in turn raises the lower lift arms of the 3-point hitch—by virtue of the fact that the rockshaft arms are connected to the lower lift arms via the aforementioned lift links; which in turn raises the implement (or portion thereof) to which the 3-point hitch is attached.
As should be apparent, a 3-point hitch is a useful way to join many kinds of pull-behind implements to a utility vehicle. This is especially true when the implement is to be raised (with the force supplied by the hydraulic system of utility vehicle) and lowered (with the force supplied by gravity) during use. For example, a utility vehicle pulling a plow that is attached using a 3-point hitch can be raised and lowered as the utility vehicle goes forward. In this way the operator of the utility vehicle can lower the plow to dig more deeply into the soil, or raise the plow to dig less deeply into the soil. Raising and lowering the implement, in this case a plow, affects the soil depth at which the implement operates and, therefore, the load on the utility vehicle. Because of its utility, a 3-point hitch has become a standardized piece of equipment on many utility vehicles. Similarly, many implements are adapted to connect to a utility vehicle using a 3-point hitch.
For some implements, however, a 3-point hitch may not be as useful, or optimal, for connecting the implement to a utility vehicle. Backhoes, for example, are used for digging. The digging motion of a backhoe can generate significant forces on the backhoe itself, and any utility vehicle to which the backhoe is attached. Unlike a pull-behind implement, which benefits from some flexibility in lateral and vertical movement during operation of the implement, a backhoe performs better if it is more rigidly attached to a utility vehicle. Accordingly, a user attaching a backhoe to a utility vehicle typically has two options: (1) remove the 3-point hitch (or move parts of the 3-point hitch, such as the lower lift arms, out of the way, and keep them out of the way, because they will not be used to attach the backhoe or other equipment to the utility vehicle), which is generally designed for a somewhat mobile and flexible connection to a pull-behind implement; or (2) modify the 3-point hitch to increase its rigidity when connecting an implement like a backhoe to the utility vehicle.
A user choosing option (1) above must remove the 3-point hitch, or parts thereof (e.g. the lower lift arms), before attaching the backhoe or other implement to the back of the utility vehicle—using, of course, another connection device to attach the backhoe. Or parts of the 3-point hitch, such as the lower lift arms, must be moved and kept out of the way, because they are not used when connecting the implement to the utility vehicle. If a user goes back and forth between operating the utility vehicle with pull-behind implements and operating the utility vehicle with other implements, then the user must also go back and forth between mounting the 3-point hitch (when attaching implements that make use of the hitch); and removing the 3-point hitch, or parts thereof (when attaching equipment such as a backhoe)—or moving and keeping parts of the 3-point hitch out of the way. This is time consuming, and inefficient.
For example, one method of attaching an implement such as a backhoe to a utility vehicle involves attaching the implement directly to the frame of the utility vehicle (typically denominated as a “subframe installation”). As discussed above, the 3-point hitch, or parts thereof (e.g., the lower lift arms), are removed. The utility vehicle is then positioned proximate to the backhoe, typically by backing up the utility vehicle so that it is near the backhoe, and the hydraulic hoses of the backhoe are then connected to the utility vehicle. The hydraulic system of the utility vehicle is then used to power the backhoe, enabling an operator to use the backhoe's controls to raise and/or lower and/or level the backhoe (e.g., by rotating the backhoe; or by adjusting the stabilizers of the backhoe) so that the backhoe is generally aligned with portions of the utility vehicle frame (specifically, the backhoe and utility vehicle are aligned such that the backhoe and/or utility vehicle may be moved so that the backhoe engages a utility vehicle mount adapted to connect to the backhoe). Generally an operator adjusting the position of the backhoe does so while standing on the ground next to the backhoe while manipulating the backhoe's controls. After the operator has aligned the utility vehicle relative to the backhoe in this manner, the utility vehicle and/or backhoe are moved so that the backhoe engages the utility vehicle mount adapted to connect to the backhoe. The backhoe is then securely connected via the utility vehicle mount to the utility vehicle, typically by inserting pins, bolts, retainers, or other such connectors.
Another method for attaching a backhoe to a utility vehicle, typically denominated as a “four point installation,” includes steps like those presented in the previous paragraph. First, the 3-point hitch, or parts thereof (e.g., the lower lift arms), are removed. Next the utility vehicle is positioned proximate to the backhoe, typically by backing up the utility vehicle so that it is near the backhoe, and the hydraulic hoses of the backhoe are then connected to the utility vehicle. The hydraulic system of the utility vehicle is then used to power the backhoe, enabling an operator to use the backhoe's controls to raise and/or lower and/or level the backhoe (e.g., by rotating the backhoe; or by adjusting the stabilizers of the backhoe) so that the backhoe is generally aligned with portions of the utility vehicle frame (specifically, the backhoe and utility vehicle are aligned such that the backhoe and/or utility vehicle may be moved so that the backhoe engages the utility vehicle frame/mount). Generally an operator adjusting the position of the backhoe does so while standing on the ground next to the backhoe while manipulating the backhoe's controls. After the operator has aligned the utility vehicle relative to the backhoe in this manner, the utility vehicle and/or backhoe are moved so that the backhoe engages the utility vehicle frame, which is adapted to connect to the backhoe. The backhoe is then securely connected via the utility vehicle mount to the utility vehicle, typically by inserting pins, bolts, retainers, or other such connectors.
A user choosing option (2), rather than removing the 3-point hitch, typically modifies the 3-point hitch to stabilize the three arms. For example, the upper link of a conventional 3-point hitch may be replaced by a longer adjustable bar that is attached to upper metal braces on either side of the bar. The upper metal braces attach to the adjustable bar and to the utility vehicle or utility vehicle. This combination of an upper adjustable bar with upper metal braces serves as one attachment between the utility vehicle and the backhoe. This upper attachment is further stabilized by connecting additional metal links between this upper combination and either the lower lift arms of the 3-point hitch or a lower portion of the frame of the backhoe itself. The lower lift arms of the 3-point hitch may also be connected directly to a lower portion of the frame of the backhoe. As discussed above, this way of attaching a backhoe works. But it takes time to modify the hitch and connect it to the backhoe. And because the 3-point hitch is designed to provide a flexible connection to pull-behind implements—e.g., ball-and-socket joints are typically employed at both ends of the 3 arms of the 3-point hitch to provide such flexibility and accommodate up-and-down and lateral movement of the implement as it is pulled—even this stabilized 3-point hitch allows some back-and-forth and up-and-down movement during operation of the backhoe. Also, the method of connecting a stabilized 3-point hitch to an implement typically requires that the hydraulic hoses of the backhoe first be connected to the utility vehicle's hydraulic system (so that the hydraulic system of the utility vehicle may be used to power the backhoe and allow an operator to use the backhoe's controls to adjust the backhoe's orientation relative to the utility vehicle). Similar to the four-point and subframe installation methods described above, this step is typically required in order to raise and/or lower and/or align the backhoe prior to securely attaching the backhoe to the utility vehicle (in this last case using the stabilized 3-point hitch).